Variable speed hydraulic clutch



Nov. 21, 1950 J. R. THOMAS 2,531,014

VARIABLE SPEED HYDRAULIC CLUTCH Filed Nov. 16, 1948 5 Sheets-Sheet 1 Nov. 21, 1950 J. R. THOMAS VARIABLE SPEED HYDRAULIC CLUTCH 5 Sheets-Sheet. 2

Filed NOV. 16, '1948 Nov. 21, 1950 Fil d Nov. 16. 1948 J. R. THOMAS VARIABLE SPEED HYDRAULIC CLUTCH S ShefetS-Sheet "3 J. R. THOMAS VARIABLE SPEED HYDRAULIC CLUTCH Nov. 21, 1950 5'-'Sheets-Shoej. 4

Filed Nov. 16, 1948 In uenior Nov. 21, 1950 J. R. THOMAS VARIABLE SPEED HYDRAULIC CLUTCH 5 Shuts-Sheet 5 Filed NOV. 16, 1948 Patented Nov. 21, 1950 VARIABLE SPEED HYDRAULIC CLUTCH John It. Thomas, Wichita, Kana, assignor to Speed Controls, Inc., Wichita, Kans., a corporation of Kansas Application November 16, 1948, Serial No. 60,270

6 Claims. (Cl. 192-61) Thomas Hydraulic This invention relates to improvements in variable speed hydraulic clutches of the type shown in my copending patent application Serial No. 717,915 filed December 23, 1946, wherein two fluids of different resistant value are employed independently as well as in mixtures of relatively varied proportions and wherein the control of the independent fluids and of their mixtures is effected through movable valve means adapted for metering and arresting the flow of the fluids passing through a fluid-circulating and powertransmitting instrumentality such as, for example, a gear type pump having elements operatively connecting the clutch casing with a driven shaft extending into the clutch casing.

The present invention has among its objects to provide certain improved structural and operative features not disclosed in prior art which materially enhance the stability and utility of hydraulic clutches of the aforementioned type, increase the efficiency thereof and enhance the scope of adaptation of same to diverse power transmission operations in a wide fleld of uses.

Another object of the invention is found in the provision of a symmetrically constructed clutch including fluid-circulating and powertransmitting means located centrally axially of the clutch casing to thereby provide a dynamically balanced rotatable body affording an appreciable reduction in cost of manufacture through symmetry in design whereby the oppositely disposed intake and discharge manifolds of a power-transmitting fluid pump may be constructed alike and whereby the clutch casing may consist of a pair of like castings disposed on and secured to opposite ends of the powertransmitting fluid pump.

Still another object of the invention resides in the provision of fluid-circulating passages extending transversely through the fluid pump for affording circulation of the fluid between the fluid chambers within opposite ends of the clutch casing thereby providing a more uniform distribution and more eflicient dissipation of the heat generated within the pump.

A further object of the invention is found in the provision of an axially symmetrically constructed clutch including a fluid-circulating and power-transmitting pump disposed centrally axially of the clutch casing and having fluid intake and discharge ports communicating with fluid chambers disposed within the casing at opposite ends of the pump including axially aligned dual valve means disposed within the fluid chambers for metering and controlling fluid flow through said ports at the intake and discharge openings thereof within manifolds disposed on opposite ends of the pump and conjoint control means adapted for controlling the operation of the dual valve means during the rotation of the clutch casing.

Still another object of the invention resides in the provision of a hydraulic clutch adapted to be interposed between power-driven means and a driven shaft and embodying a rotatable casing partiallly filled with oil whereby, during the rotation of the casing, there is provided within the casing an outer annular zone of oil and an inner central zone of air, including a powertransmitting pump provided with fluid intake ports having inlet openings on one end of the pump and discharge ports having discharge openings on the opposite end of the pump, the pump having elements operatively connected with the casing and with the driven shaft and being disposed centrally axially of and within the casing thereby dividing the interior of the casing into two axially spaced intercommunicating chambers and each chamber containing a valve for controlling the metering and circulation of fluid through the pump from one chamber to the other, one of the valves controlling the flow of fluid through the inlet openings into the intake ports and the other valve controlling the flow of fluid through the discharge openings of the discharge ports, the valves being disposed within both of said zones and movable by conjoint control means within both of said zones to control the flow of air, or of mixtures of air and oil, or of oil, or of neither, through the pump to thereby control the stationary position or relatively variable rotations of the driven shaft during the rotation of the casing by the powerdriven means.

The various features of novelty whereby the present invention is characterized will hereinafter be pointed out with particularity in the appended claims; but, for a full understanding of the invention and of its variousobi cts and advantages, reference may be had to the following detailed description taken in connection with the accompanying drawings exemplifying a preferred embodiment of the invention which is now considered to be the best mode of applying the novel principles of the invention.

The illustrations in the drawings, in which like reference characters designate like or corre-- sponding parts, may be described as follows:

Fig. 1 illustrates a longitudinal section through a hydraulic clutchembodying my invention; the

fluid-circulating and power-transmitting pump and the dual fluid metering means are shown in longitudinal section taken on line A-A of Fig. 5.

Fig. 2 illustrates a one-half end view of the clutch as viewed from the right-hand side of the clutch shown in Fig. l; the illustration of the portion shown on the right-hand side of Fig. 2 is a one-half face view of one of the valves taken on line 22 of Fig. 1- showing also the outer side portions of one of the manifolds and the pump body but with the clutch casing omitted from the illustration.

Figs. 3 and 4 are fragmentary cross-sections taken respectively on lines 33 and 4-l of Fig. 1; the clutch casing being omitted.

Fig. 5 is a cross-section taken on line 5-5 of Fig. 1; the clutch casing being omitted.

Figs. 6 and 7 are cross-sections taken respectively on lines B6 and 1-1 of Fig. 5.

Fig. 8 is a cross-section taken on line 38 of I Fig. 1.

Fig. 9 is a fragmentary longitudinal section showing the dual valve means provided with modified connecting rods and illustrating the manner of phase adjustment of the control for the dual valve means.

In the preferred exempliflcation of my invention as illustrated in the accompanying drawings, the clutch casing, generally designated by numeral 20, comprises a pair of like cup-shaped sections and 20 preferably of cast metal, each consisting of an arcuate wall portion 2i provided at its inner end with an integral cylindrical wall portion 22 and, at its outer periphery, with an integral connection flange 23. For heat dissipating purposes, the outer face of each wall portion 2| is preferably provided with radially disposed circumferentially spaced ribs 24 which conform to the contour of the wall portion 2i and extend, as reenforcing ribs, from the wall portion 22 to the connection flange 23.

The power-driven drive shaft 25 is provided with an enlarged head 26 which is supported within the cylindrical wall 22 and by means of its flange 26 and screws 21 is rigidly secured to the casing section 20 The oppositely disposed companion casing section 20 is shown provided with a flanged hub 28 mounted within its cylindrical wall 22 and secured thereto by screws 29.

.The hub 28 carries an oil seal 30 and a ball bearing 3| in which is rotatably mounted the driven shaft 32 the inner end of which is diametrically decreased and rotatably supported on a suitable bearing 33 securely mounted within a suitable cavity formed within the inner face of the head 26 of the drive shaft 25.

The centrally axially disposed fluid-circulating and power-transmitting instrumentality is illustrated as a gear type fluid pump having a circularly shaped body 34.

The peipheral flanges 23 of the casing sections 20 and 20 are rigidly secured to the peripheral rim portion of the pump body 34 which is thus centrally axially supported within the casing 20.

As more clearly shown in Figs. 1 and 5, the pump body 34 is circular in shape and has a central bore 35 containing a sun gear 36 which is secured by key 31 to the driven shaft 32. As shown in Fig. 5, the bore 35 is provided with three arcuate openings in its periphery which communicate with three circularly equally spaced bores 38 each containing a planet gear 39 in mesh with the sun ear 36. Assuming that the rotation of the clutch is clockwise as indi- 4 cated by the arrow in Fig. 5, between each pair of planet gears 38. the pump body 34 is provided with a fluid intake port 40 and a fluid discharge port ll.

The sun gear bore or cavity 35 and planet gear bores or cavities 38 extend transversely through the opposed parallel end faces of the pump body 34. The corresponding end portions of the arcuate walls which define the planet gear cavities 38 are slightly recessed, as at 38', to provide thereat slightly enlarged cavities which communicate with the inner ends of the intake and discharge ports whereat such inner ends the intake and discharge ports are enlarged to extend substantially across the full thickness or width of the pump body as illustrated in Fig. 6.

In the three planet gear body shown in the drawings. the intake and discharge ports extend therein in the form of a triangularly shaped circuit, the series of inlet openings 40 for the intake ports 40 and the series of outlet openings 4|" for the discharge ports 4| are located on opposite ends of the pump body and the inlet opening 40 of an intake port 40 for each planet gear cavity 38 is axially aligned with an outlet opening M of a discharge port ll of an adjacent one of the planet gear cavities and such axially aligned intake and discharge openings are located midway between and communicate with opposite sides of cavities for two of the planet gears.

Each intake port 40 is provided with an inwardly flaring outlet opening 40' similar in configuration to the inlet opening ll of a discharge port 4| shown in Fig. 6. To provide cross flow of the fluids between the chambers disposed at opposite ends of the pump transversely through the pump body 34, the sun gear 36 is provided with a plurality of transverse open passages 42 disposed within the air zone and, in addition, the pump body is provided with transver e open passages 43 and 44 disposed within the oil zone.

Each planet gear 39 is provided with a suitable antifriction bearing 45 for rotation on a tubular pin 46 which is securely held by a bolt H which extends longitudinally through the planet pin 46 and through the suction and discharge manifolds designated by respectively numerals l8 am 48 The planet pins 46 have diametrically decreased ends for support within recesses in the manifolds as more clearly shown in Fig. 1.

To improve the efliciency of the gear type pump, I slightly recess the opposite ends of the gears. The recesses are clearly shown in Figs. 1 and 5; the circular recesses in the planet gears 39 are designated by numeral 3!! and those in the sun gear 36 by numeral 36*. These circular recesses are preferably of a depth of about to A; of an inch and extend radially outwardly to within a predetermined distance from the root circle of the teeth and function to reduce the drag torque transmitted to the driven shaft 32. For lubrication purposes, the planet gears 39 are each preferably provided with a plurality of circularly equally spaced transverse passages 39 The two like sections 20 and 20 of the casin 20 are securely bolted to the peripheral rim portion 34 of the pump body 34 by circularly equally spaced bolts 50.

In carrying out the symmetry of design, as in the si ilar casing sections 203 and 20 the two manifold plat s 48 and 48 are identical as far as the castings constituting their bodies are concerned and each manifold plate consists of a transverse wall portion 45 having an axially extending integral cylindrical wall portion 45 disposed concentrically with the longitudinal axes of the drive shaft and the driven shaft 52 and constituting a valve seat.

Each manifold is cast with a plurality of peripherally disposed circularly spaced lugs 45 and 45 formed integrally with and within the plane of the transverse wall portion 48 and extending radially outwardly beyond the transverse portion at". The lugs 45* and 48 are provided with openings to receive bolts 49 whereby the two manifolds are secured to opposite sides of the pump body 34.

Each manifold is provided with a comparatively large central opening 48 which is concentric with the driven shaft 32. These manifold openings afford free passage of fluid between the fluid chambers on the opposite ends of the pump through the manifolds and through openings 43 and 44 in the pump body 24 and through the passages 42 of the sun gear 55.

Each manifold is cast with an annular pressurestabilizing port 48 disposed within the peripheral face of the axially disposed wall or valve seal 45.

Circular pre-loaded closure rings 50 are applied upon the peripheral faces of walls 48 to enclose the pressure-stabilizing ports 48".

The pressure-stabilizing port 48 in the suction manifold- 48 is provided with three circularly equally spaced elongated manifold intake ports 45- which register and communicate with the three inlet openings of the three intake ports 40 within the pump body 54. The port 48 in the suction manifold 48 is also provided with a plurality of circularly equally spaced intake openings 48' within the cylindrical wall 48 which constitutes the valve seat for the suction valve 5 later to be described.

The pressure-stabilizing port 48 in the discharge manifold 48. is rovided with three circularly equally spaced elongated manifold discharge ports 48 which register and communicate with the three outlet openings 4| of the three discharge ports 4! within the pump body 34.

The port 48 in the discharge manifold is also provided with a plurality of circularly equally spaced discharge openings within the cylindrical wall 48 which constitutes the valve seat for the discharge valve 5| late to be described. For most eflicient clutch operation, these discharge openings are preferably circularly arranged in series each series comprising a plurality of discharge openings of at least two different diameters and all of the discharge openings of all series having edges" circularly aligned in a common plane as, for example, with the lane of the face of the outer side wall of the pressure-stabilizing port 48 as indicated in Fig. 1. Each series may also consist of several individual openings each of different diameter and pairs of openings differing in diameters from the diameters of the individual openings as, for example, Fig. 3 shows each of the series of discharge openings as consisting of two small holes 48", 48", two slightly larger holes 48", 48"; one still larger hole 45; and one largest hole 45 Thus each of the four series consisting of six openings.

The movable fluid control valve means comprises a pair of axially spaced valves of similar cylindrical unitary structure, namely, a fluid intake control or suction valve 50 and a fluid discharge control valve 5|. Since these valves are similar, their similar structural elements are herein designated by like reference characters and each valve may be described as consisting of a pair of diametrically disposed axially spaced walls 52 and 53 of like diameter slidably mounted within the valve seats 48 of the suction and discharge manifolds, respectively designated by 45 and 45 The walls 52 and 53 are provided with central openings 54 to permit free flow of fluid around the driven shaft 32 through the passages between the walls 52 and 53.

Each valve 50 and 5| is provided with preferably three large open fluid passages 55 extending axially of the valve transversely through the walls 52 and 53. The fluid passages 55 are preferably of substantially triangular shape and are deflned by triangig'arly disposed enclosure walls 56 which extend transversely through the passages between the walls 52 and 53 and are formed integrally therewith to seal the three transverse passages 55 from communication with the three radially disposed passages between the walls 52 and 55.

Referring now particularly to the fluid intake or suction control valve 50 which controls the flow of air, mixtures of air and oil, or of only oil into the gear type power transmission pump, this valve 50 is cast with an inwardly axially disposed circular fluid flow control rim 51 which is provided with an annular oil inlet channel 51 disposed within the peripheral face of the rim 51 adjacent the circular fluid metering control rim portion 51 which is provided with a comparatively very narrow peripheral face in slidable engagement with the face of the valve seat 4i! as clearly shown in Figs. 1 and 9.-

During the rotation of the clutch casing, which is partially fllled with oil, the oil will assume annulus form to provide a central core of air which for illustration is defined by the dot and dash lines designated by X.

The oil inlet channel 51, which during the rotation of the clutch is disposed within the oil annulus, has open communication with the oil annulus through the circularly spaced arcuate oil inlet openings 51 which consist of circularly spaced slots within the peripheral face of the rim 51 as more clearly shown in Figs. 1, 8 and 9.

The radially outwardly flaring passages 55 disposed between the axially spaced walls 52 and 52 of the fluid intake control valve 50 are radially defined by the walls 55 and constitute radially outwardly flaring open air intake passages for flow of air from the central zone of air admitted thereinto through the central valve openings 54 for discharge through their open outlets within the peripheral portion of the valve in to the valve seat intake openings 48 when the intake control valve 50 is positioned to communicate therewith as illustrated in Fig. 1.

The intake control valve 50 may also be provided with additional transverse fluid passages, to enhance the free flow of fluids between the opposite ends of the valve, in the form of circular passages 55 defined by the circular enclosure walls 55 which extend transversely through the radially outwardly flaring passages between the walls 52 and 55 and which walls v55 are formed integrally therewith to seal the passages 55 from communication with the radially outwardly flaring passages 55 between the walls 52 and 53.

As illustrated in Figs. 1 and 9, the valves 55 and 5| are arranged for concurrent operation and for this purpose the valve 50 is provided with three circularly equally spaced bosses 50 cast integrally with the walls 52 and 52 and extending through the air inlet passages 50* and protruding inwardly a predetermined distance to constitute limit stops for concurrent movement of both valves 50 and BI when moved to the right as viewed in Figs. 1 and 9 into engagement with aligned bosses on the suction manifold 4| whereat valve 50 is properly positioned for neutral clutch operation with the air inlet passages 50* aligned with the suction manifold valve seat intake openings 48.

The concurrent operation of valves 50 and SI is attained by connection rods 8| which extend through the bosses 60 and through similar bosses 62 on valve 5|; the valves 50 and lil being accurately spaced apart a predetermined distance and so retained by means of spacers 63 in the form of sleeves mounted on the rods 6i and having their ends in abutment with the opposed ends of bosses to and 82.

The connection rods BI and their spacer sleeves 43 extend through openings 84 extending through the pump body 34 as clearly shown in Figs. 1, 5 and 9.

Referring further to the structure of the fluid discharge control valve 5| as illustrated in Figs. 1, 2, 3, and 9, this valve Si is provided with an outwardly axially disposed circular fluid discharge control rim 65 cast integrally with the wall 53 and the circular peripheral face of the rim 6! is slidably engaged with the valve seat 48 of the discharge manifold 48 and axially aligned withthe peripheral comparatively narrower face of the wall 52.

The radially outwardly flaring passages BI disposed between the axially spaced walls 52 and II of the fluid discharge control valve ii are radially defined by the walls 56 and constitute open exhaust-fluid discharge passages for air, or mixtures of air and oil, or of only oil as these fluids are discharged from the pump discharge ports 4| through the manifold discharge ports 48 and the valve seat discharge openings. The'valves 50 and BI which are rigidly connected together by the rods 8| are adapted to be concurrently shifted axially into various operative positions by conjoint control means including three valve shift rods 66 which extend inwardly into 'a hub 61 cast integrally with the wall 52 of the fluid discharge control valve 5| and are secured at the inner ends to the hub 61 by a snap ring 88. As'shown in Figs. 1 and 3, the walls 56 are formed with integral bosses 56 through which the shift rods 88 extend and which bosses 58 seal the cylindrical passages for the shift rods from communication with the fluid passages 6|. The shift rods 66 are slidably supported in the bushings 69 and seals 10 which are carried in the enlarged head 26 of the powerdriven shaft 25 and their outer ends are secured to the shifter sleeve II, as by a snap ring 12.

The shifter sleeve H is supported on and rotatable with the power-driven shaft 25 and enclosed within the shifter collar 13 which is carried on a ball-bearing I4 interposed between the shifter collar 13 and the shifter sleeve 1 I, the collar 13 being retained against axial movement relatively to the shifter sleeve II as by a snap ring 15 seated in the outer end of the shifter sleeve ll against the space ring 18, however, the valve shifter sleeve H is axially shiftable to conjointly shift the valves 50 and SI relatively to the rotatable power-driven shaft 25 and clutch casing by the non-rotatable shifter collar 13 which is provided with diametrically oppositely disposed studs ll which are continuously engaged by the 8 forked end 11 of the valve shifting lever 11 which is pivotally supported on the pivot rod 14 suitably supported on a stationary support not shown.

The power-driven shaft 25 is shown in .Fig. 'l with an outwardly extended end provided with a keyway 25 for rigid securement thereto of any suitable drive pulley or sprocket.

It will now be apparent that the intake control valve 50 is provided with a plurality of radially outwardly flaring air inlet passages which extend outwardly from the valve central openings 54 within the air zone and merge into the circular peripheral space between the spaced walls 52 and 53 within the zone of the oil annulus. The discharge control valve BI is provided with a plurality of radially disposed open discharge passages BI which extend from their common circular in-. take space disposed between the peripheral portions of the walls 52 and 53 within the zone of the oil annulus and converge radially inwardly to their common discharge openings 54 in the central portion of the valve within the air zone which is, for illustrative purposes, defined by the lines X in Figs. 1, 8 and 9.

Without giving consideration to the metering control of the fluids by the concurrent action of the valves 50 and 5!, the fluid flow circuit may best be described as follows:

Assuming that the direction of rotation of the clutch casing is clockwise as viewed in Figs. 2, 3, 4, 5 and 8, all fluids, such as only air admitted into the inlet passages 5i! of the intake control valve 50, or mixtures of air with oil admitted through the oil inlet openings 51, or only oil admitted through the oil inlet openings 51, pass through and from the peripheral control rim of valve 50 through the valve seat intake openings 48 directly into the pressure-stabilizing port 48 of the suction manifold 48*, thence into the manifold intake ports 48-, thence through the pump intake ports into the chambers of the pump disposed between the planet gears and the sun gear, thence around the planet gears 38 within the gear cavities 38 and around the sun gear 36 within its cavity 35 and therefrom into the discharge ports 4|.

From the pump discharge ports 4!, the fluids pass into the manifold discharge ports 48 and thence into the discharge manifold pressurestabilizing port 48 and through the valve seat openings whereat the discharge of the air, or mixtures of air and oil, or only oil, or neither is controlled by the peripheral rim of valve 5!; the air, or mixtures of air and oil, or only oil being adapted to pass from the valve seat openings in the discharge manifold 48 through the valve discharge passages 5H and central openings 54 into the clutch casing.

As shown in Fig. 1, the valves and 5| are in neutral position and, with the clutch casing rotating in clockwise direction as heretofore assumed, only air from the central air zone is being admitted into the radial inlet passages 50* which, under the suction created within the gear pump, passes through the valve seat intake openings 48 for circulation through the intake manifold 48 and through the pump, as described hereinabove, and thence through the discharge ports 48 of manifold 48 and through its valve seat openings into and through the discharge passages 61- and through the outlet openings 54 of the discharge control valve 5| into the central air zone.

Although the peripheral flow control rim of the intake control valve 50 is constantly within the oil annulus during the rotation. of the clutch casing so that the oil is free to pass through the circularly spaced openings 51 therein, the oil, during such neutral operation, is sealed from passing into the valve seat intake openings 48 by the narrow circular sealing face of wall 53 which separates the circular oil inlet channel 51 from the peripheral annular air discharge channel between the walls 52 and 53 into which merge all three radial passages 50. Under such neutral operation the driven shaft 32 for all practical purposes is unoperative or in stationary position.

The fluid metering and speed controlling operation of the valves 50 and will readily be understood by reference to Fig. 1.

A progressive movement of the operating lever ll toward the right will cause a progressive and simultaneous movement of both valves 5|! and 5| toward the left and during such valve movement the flow of the fluids into, through and out of the power-transmitting pump will cause a progressively decreased flow of air into the pump while a progressively increased flow of oil will be admitted for admixture with the air until only oil is being admitted into the pump through the valve seat intake openings 48 thus interposing between the pump gears a mixture of fluids or finally only oil of progressively increased resistant value to thereby impart a progressively increased torque and speed to the driven shaft 32.

The manner in which the peripheral rim of the intake valve 50 causes a progressively increased flow of oil into a admixture with the simultaneously progressively decreased flow of air into the power transmitting pump to increase the torque and speed of the driven shaft 32 will be readily understood by referring to Fig. l and visualizing the progressive movement of the peripheral rim of valve 50 toward the left and particularly the successive positions of the narrow circular rim face of the valve wall 53 relatively to the intake openings 48 As this valve wall 53 moves progressively toward the left, progressively increased areas of the open valve seat intake openings 48 will be exposed to open communication with the oil flowing through the circularly spaced oil inlet openings 51 into the channel 51 and thence into the valve seat openings 48* while simultaneously the areas of the valve seat openin s 48 which are in open communication with the radial air inlet passages 50 are progressively decreased.

While the torque and speed of the driven shaft 32, are progressively increased by the above described progressively increasing resistant value of the fluid passing into the pump, the torque and speed increase is further enhanced by the concurrent movement of the flow discharge control valve 5| simultaneously progressively closing the valve seat openings in the discharge manifold 8 When the peripheral rim of wall 53 of the intake valve 50 has moved past the valve seat intake openings 48 the air outlet channel between the peripheral portions of walls 52 and 53 will then be closed by the outer portion of the valve seat 48 so that no air but onl oil can pass into the valve seat openings 48 however, at this position of the valve 50, the discharge control valve 5| will have moved toward the left a suflicient distance whereat its rim 65 has completely closed all of the discharge openings in the valve seat for the discharge valve 5| thus fully arresting the flow of oil from the pump and thereby causing the driven shaft to rotate in substantially one to one ratio with the driving shaft.

Phase adjustment of control valves 50' and 5| is illustrated in Fig. 9 wherein the bosses 62' are comparatively shorter than the bosses 62 shown in Fig. 1 thereby advancing the initial position of the discharge control valve 5| a predetermined distance inwardly or closer toward the intake control valve 50, which is shown in Fig. 9 in the same position as in Fig. 1, thus in such advanced initial position, without any disadvantage, slightly restricting the discharged flow of air during neutral operation of the clutch to thereby shorten the period of neutral operation in order to attain quicker increase in torque and speed of the driven shaft 32 within the same length of concurrent movement of the control valves 50 and 5|. Obviously, the intake control valve 50 moves the same distance when the discharge control valve 5| is adjusted as shown in Fig. 9 that it does in the valve arrangement shown in Fig. 1 to provide identical metering of fluids.

I claim:

1. A variable speed hydraulic coupling adapted to be interposed between rotatable power-driven means and a driven shaft and comprising a rotatable casing having therein a pair of axially spaced intercommunicating chambers partially fllled with oil whereby, during the rotation of said casing, there is provided in said chambers an outer annular zone of oil and an inner central zone of air; a cylindrical fluid-intake valve seat and a separate cylindrical fluid-discharge valve seat, said valve seats being axially spaced from each other and both being disposed in said zone of oil; fluid-circulating power transmitting means positioned axially between said valve seats including ports providing fluid circuits having intake openings in said intake valve seat and discharge openings in said discharge valve seat and including relatively movable coacting powertransmitting elements operatively connecting said casing with said driven shaft; a cylindrical fluidintake control valve having a peripheral fluidmetering rim disposed within the zone of oil and being movably mouned on said intake valve seat and having a plurality of radially disposed air passages provided with air inlet openings in the central portion of said intake valve within the zone of air and air discharge openings within said rim, said intake control valve being adapted to control and meter the flow of air or oil or mixtures of air and oil into said port circuits; a cylindrical fluid-discharge control valve spaced axially from said fluid-intake control valve and having a peripheral rim disposed within the zone of oil, movably mounted on said discharge valve seat, adapted to control and meter the flow of fluids out of said port circuits, said discharge valve including a plurality of radially disposed exhaust fluid passages having fluid inlet openings in said rim thereof and fluid discharge openings in the central portion of said discharge valve within the zone of air; and conjoint control means for moving said valves to control the fluid flow through said port circuits.

2. A variable speed hydraulic coupling as set forth in claim 1 wherein said fluid-intake valve seat is provided with an annular fluid-intake pressure-stabilizing port communicating. with, and interposed between, said intake-valve-seat openings and the intake ends of the ports of said circuits, and wherein said discharge valve seat is p ovided with an annular exhaust fluid pressurestabilizing port communicating with, and interposed between, said discharge-valve-seat discharge openings and the discharge ends of the ports of said circuits. and wherein the fluid metering rim of said intake control valve. is adapted to control and meter the flow of the mixtures of air and oil in relatively varied proportions into said intake-valve-seat intake openings, and wherein the fluid metering rim of said discharge control valve is provided with a rim extension which is adapted to completely arrest the discharge of fluid from said discharge-vaive-seat discharge openings, and wherein said conjoint control means for said valves is adapted to move said valves concurrently axially on said valve seats.

3. A variable speed hydraulic coupling as set forth in claim 2 wherein said discharge-valveseat discharge openings consist of a plurality of circularly spaced openings of at least two different diameters all having edges aligned in a common plane extending transversely to the axis of the clutch.

4. In a variable power and speed transmitting hydraulic clutch including a rotatable casing, fluid-circulating power-transmitting pumping means operatively connected with a driven shaft extending iinto said casing, said pumping means being disposed axially intermediate opposed'ends of said casing thereby dividing the interior of said easing into a pair of axially spaced fluid chambers, and having fluid intake and discharge manifolds at opposite ends thereof provided respectively with intake and discharge ports communicating with said pumping means and with said axially spaced chambers, a cylindrical valve seat on each of said manifolds, said valve seats having openings communicating respectively with said intake and discharge ports, said casing being partially filled with oil whereby, during its rotation, there is provided in said chambers an outer annular zone of oil and an inner central zone of air, a cylindrical fluid intake control valve movably mounted on the intake manifold valve seat including means on said intake control valve adapted to control and meter the flow of only air, or mixtures of relatively varied proportions of air and oil, or only oil through, and responsively to its movement relatively to, the intake valve seat openings, a cylindrical fluid discharge control valve movably mounted on the discharge manifold valve seat including means on said discharge control valve adapted to control and meter the fluid flow through, and responsively to its move- 12 ment relatively to, the discharge valve seat openlugs, and conjoint control means for said valves arranged to move said valves concurrently on said manifold valve seats.

5. In a variable power and speed transmitting hydraulic clutch as set forth in claim 4 wherein said intake control valve comprises a pair of parallel axially spaced circular walls of like diameters, and wherein said means on said intake control valve adapted to control and meter the flow ofsaid fluids comprises an air passage disposed between said parallel axially spaced circular walls provided with air inlet openings in the centers of said walls within the zone of air and an air discharge opening between the peripheries of said walls, and including at least one opening within the oil annulus extending transversely through said walls and through said air passage and sealed from communication with said air passage for permitting flow of oil in the chamber containing said intake control valve between opposite ends of said intake control valve.

6. In a variable power and speed transmitting hydraulic clutch as set forth in claim 4 and wherein said discharge control valve comprises a pair of parallel axially spaced circular walls of like diameters, and wherein said means on said discharge control valve adapted to control and meter the flow of fluids comprises a fluid discharge passage disposed between said parallel axially spaced circular walls provided with an annular fluid inlet opening between the periphcries of said walls and fluid discharge openings within the centers of said walls, and including a plurality of openings within the oil annulus extending transversely through said parallel walls and through said fluid discharge passage and sealed from communication with'said fluid discharge passage ior permitting flow of oil in the chamber containing said discharge control valve between opposite ends of said discharge control valve.

JOHN R. THOMAS.

REFERENCES CITED The following references are of record in the flle of this patent:

UNITED STATES PATENTS Number Name Date Re. 22,577 Thomas Dec. 12, 1944 471,656 Strong Mar. 29, 1892 

